As will be well known to those skilled in the art, a Storz-type coupling has a pair of coupling components which are coupled together and rotated so as to secure such components together, e.g. for connecting together a pair of hoses connected to respective ones of the coupling components or for securing a hose to a fire pump on a firetruck.
As is also known to those skilled in the art, it sometimes happens that, as a result of incorrect rotation of the coupling parts when they are connected together, and/or as a consequence of twisting in the hose from the laying of the hose or from the design of the hose, the coupling tends to be automatically and accidently uncoupled when the hose is used. In this condition it should be born in mind that a large volume firehose may have a pressure of approximately 75 to 125 p.s.i., and also that the twisting is transmitted through the hose until it reaches the last coupling, i.e. the coupling connected to the pump of the firetruck or other pumping apparatus.
Consequently, it is found that the coupling is sometimes caused to back off and release. This results in a potentially lethal uncontrolled large volume hose at pressure in the work area of operators already functioning under emergency conditions.
Proposals have, in the past, been made for releasably securing or locking together the two components of a Storz firehose coupling for counteracting such accidental release of the coupling.
Thus, U.S. Pat. No. 4,648,630, issued Mar. 10, 1987 to George H. Bruch discloses a firehose coupling locking device which is permanently attached to a collar on the highpressure outlet side of a fire pumper and is pivotable so as to span the coupling pieces of the firehose and to engage the collar on the firehose and, thereby, to prevent relative rotation of the collars when water under high pressure is forced through the coupling.
This prior locking device, however, has a disadvantage that it cannot be used satisfactorily to couple a pair of hoses, since the locking device would tend to be displaced and released if the coupled hoses, together with the locking device, were dragged along the ground.